Abstract : An experiment was conducted near borehole 6010 off the New Jersey coast as part of the DARPA ACT II experiment in 1993. Several of the tow tracks of the sound source coincided with tracks from the 1988 Hudson Canyon experiment. For this experiment major differences from 1988 were the accuracy and sampling of the range data, the available sound source which dictated the use of pulses as opposed to CW, and the low signal transmit power at the lower frequencies. Horizontal wavenumber spectra were computed at 100 Hz signal for this experiment and compared with SAFARI calculations. However the 100 Hz signal levels were problematic an consequently the low received signal-to-noise ratio precluded meaningful analysis. At the higher frequencies, the coarseness of the range sampling, although adequate for signal transmission studies, would be aliased in synthetic aperture processing. Despite these problems, these results underline the robustness of this horizontal wavenumber estimation technique